TDI Timing Revisited

[jcrews]

In my experience, the timing values will converge not far above idle. Don't worry about it. Mine is at about 120/60 and I got 53 mpg with a lot of 75 mph.

If you didn't put a lot of miles on it, a small fuel quantity can have drastic effects on the MPG reading. I try to fuel up with the tank low so any quantity error is marginalized.

 

[whitedog]

I am wondering about the accuracy of the fuel mileage tests. How far did you drive and how did you measure fuel economy?

 

[greengeeker]

I'd be curious to know the effects your timing adjustments had on your scangauge readings. I know when I had my EGR disconnected for a stint my SG was reading much higher than actual. I'm not saying your findings are wrong - I'm not experiencing an increase in mileage either.

 

[npdimonte]

I am wondering about the accuracy of the fuel mileage tests. How far did you drive and how did you measure fuel economy?

Sorry for the delay. The test was short and by no means is my normal way of testing mpg. I live in the Chicago area so my first test I planed a route on the interstates that would create a large loop that would allow most of my driving to be at 70 mph. I had two choices, one that took 3 hour or another that took 4 hours on google maps. I chose the 3 hour loop. I filled the tank to the fuel cap using a gas station that was next to the interstate I planned on using. The loop brought me back to this same station where I filled the tank again to the cap. That was the 48.7 mpg at 165 mile drive.

Second test, I once again top off my tank to the cap, but this time I was 4 miles from the interstate. I had to picked up my daughter from college that evening, but since she is only an hour away, I drove past her exit on the interstate for about 20 minutes before turning around. Her college is about 3-4 miles from the interstate, so this second test was not all highway driving. But, I still managed to drive 160.5 miles for this test and I filled up again to the cap to measure my MPG. This time I got 56.7 mpg.

I concede that these are one time small samples, but that first test I could not have asked for better driving conditions. I had less favorable times in the past and was able to get 53mpg.

In a couple of weeks I plan on several small trips plus a long 9 hour trip down South. This will give me a better average of my mpg. I'll report later when I get the results.

 

[npdimonte]

An update on performance and mpg with timing still a little advanced. Regarding mpg, I did another 168.5 mile run, mostly highway @ 65 or 70mph. Used 3.035 gallon, so mpg is 55.52.

While mpg is up, I did notice that my Jetta is not as peppy as when the timing was dead center as aNUT suggested.

I may be getting great mpg, but I wonder how it will do when I'm not driving on flat land like that in Illinois. A couple of weeks I'll have a chance to test that through Kentucky, Tennessee and Alabama. Before my TB change, my Jetta never complained going up those big hills with the cruse on. My others cars always started to slow down while climbing them. If the Jetta show signs of struggling, I may retard the timing slightly to give it that extra power range that aNUT was talking about.

I'll post results as I get them.

 

[runonbeer]

Just chip it. You'll never have to worry about another hill ever again.

 

[Keebler145]

Just chip it. You'll never have to worry about another hill ever again.

What he said lol. I have my timing around 110/70 and at idle specified is 3.1 and actual is also 3.1 seems after the car has been at NOT for about 20 minutes both those numbers at idle drop to about 2.8. Not noticing any real driving issues but the engine seems quiter than it used to and much more peppy. I'll find out the fuel mileage soon hopefully.

 

[npdimonte]

What he said lol. I have my timing around 110/70 and at idle specified is 3.1 and actual is also 3.1 seems after the car has been at NOT for about 20 minutes both those numbers at idle drop to about 2.8. Not noticing any real driving issues but the engine seems quiter than it used to and much more peppy. I'll find out the fuel mileage soon hopefully.

Thanks, all this diesel stuff is new to me, so I'm learning every time I touch my Jetta and this site has been a tremendous help. Is yours chipped?

 

[matt.m]

I seem to remember my mechanic (a trusted mechanic on the boards) mentioning that VW sent out a bulletin recommending to advance the timing to some degree from their original recommending setting (I'm assuming their original recommendation was set dead center). So I was under the impression that the advancement wasn't just TDI club "dogma".

mm

 

[Keebler145]

Yeah I have an RC4 tune on my car. I usually still get pretty good fuel mileage on it, but since this nicer warm dry weather has came about my mileage has dropped to 42 . But my tires are wearing noticeable faster too so I think I may just be driving way to aggressively I really should stop flooring it every day when I go to get on the freeway lol

 

[kwalsh24]

Okay so question... I did my timing a month ago, but the guid I read didnt speak of doing this adjustment. I was just wondering what is best to have, the car set to 1.1 or 3.0 BTDC?

My car is slightly hard starting after sitting for a while and starts up with a smokey haze, and it looks like burnt oil but smells like unburnt diesel....?

My car was set to 2.0 i believe and I adjusted it to 3.0 lastnight after reading this but I now question which is best for a daily driver application... Mainly long distance driving with a mix of city driving.

 

[whitedog]

Okay so question... I did my timing a month ago, but the guid I read didnt speak of doing this adjustment. I was just wondering what is best to have, the car set to 1.1 or 3.0 BTDC?

My car is slightly hard starting after sitting for a while and starts up with a smokey haze, and it looks like burnt oil but smells like unburnt diesel....?

My car was set to 2.0 i believe and I adjusted it to 3.0 lastnight after reading this but I now question which is best for a daily driver application... Mainly long distance driving with a mix of city driving.

Those numbers show that you aren't in basic settings when you are checking the basic timing.

Read the first post. He goes step by step into how to check the timing in Basic settings. Right under the first screen shot it tells you to go to basic settings.

 

[nicklockard]

At 2000 rpm on a flat highway driving 65 mph I'm at 10 BTDC and max egr valve duty cycle.

 

[bifster]

When using the VW computer would you simply go into Basic settings? to view the timming? when i do this with the vw scantool it shows me 0* do i simply keep cranking the pump ahead till it reads 50-60? the only time I get a real number is when I read the value (NOT) in basic. The pump timing was done properly with alignment tools and all but nuthing seems to change my 0* readings in basic settings.?????

 

[aNUT]

Just chip it. You'll never have to worry about another hill ever again.

YOUR WELCOME

 

[volkswarren]

What is the duty cycle? If I set my timing to dead on or retarded in the tdi-timing I get my duty cycle jump to 60-80%, I have had to advance it to 65 in the tdi-timing to get 4% duty cycle and my actual start is now 3.5 btdc.

 

[volkswarren]

Bump? Anyone?

 

[hoover1]

i'am looking for the timing settings for a 1996 tdi passat ?can anyone help me?

 

[aNUT]

i'am looking for the timing settings for a 1996 tdi passat ?can anyone help me?

Put it on the blue line. If you want to be a nerd (like me) check group 004 afterward and see if actual matches specified.

 

[greenskeeper]

Put it on the blue line. If you want to be a nerd (like me) check group 004 afterward and see if actual matches specified.

This can help limit shuddering in AHU/1Z engines.

 

[jollyGreenGiant]

Interesting post. Now I need to experiment...

 

[greenskeeper]

There are a few tweaks other than timing, but my TDI even with the mods does not shudder at all....any gear...any rpm...any load...just smooth motor that pulls!

 

[memphis tdi]

2000 Beetle/5 spd, gets around 38 mpg(PP520s), timing is showing 78-83 in vag com, will this cause the poor milage ?

Have to go to the stealership to get the new non stretch bolts for the pump pulley, so I can adjust it.

 

[paramedick]

2000 Beetle/5 spd, gets around 38 mpg(PP520s), timing is showing 78-83 in vag com, will this cause the poor milage ?

Have to go to the stealership to get the new non stretch bolts for the pump pulley, so I can adjust it.

It's a bit advanced. Pull it back to midway between the top and middle lines on the VCDS timing graph.

 

[greenskeeper]

I hardly use the tdi timing checker anymore. I set the timing based on sound going from basic to standard settings, which to me tells how much the ECU is compensating from basic timing. Also the request vs actual should match and the sound should change little when going from basic to standard. If that makes sense?!

My car with the mods is well above the upper line in the timing checker. However I have never gotten better milage or performance and no shudder at all.

 

[arinb12]

i tryed this on my gttdi130 mkiv 2003 but my engine code isnt in the dropdown list (ASZ)

how can i check my timing?

 

[Dankcorey22]

is there any advantages to having advanced timing just a tiny bit over the green line?

 

[TornadoRed]

is there any advantages to having advanced timing just a tiny bit over the green line?

Probably not, that is just a little bit too advanced. Someone else may explain what harm, if any, might result from timing that is too advanced.

 

[aNUT]

Probably not, that is just a little bit too advanced. Someone else may explain what harm, if any, might result from timing that is too advanced.

It's not going to hurt anything, but it isn't going to help either. Just makes your car loud at idle and reduces mileage when cruising.

The mechanical limits of the advance mechanism allow the ECU to get all the advance it wants with the timing set within spec.

 

[eb2143]

This past weekend I asked Paramedick to retard my timing some. He moved it from halfway between the middle and upper line to just below the middle line. This is where specified and actual seemed to match.

• Feels smoother on acceleration.
• There is little to no shudder when you suddenly let off the go-pedal.
• Could be my imagination, but it also feels quicker..

Resurrecting....Just did this, I agree with these three observations (can't comment on EGTs).
We'll see about fuel economy and cold starts.